1. Field of the Invention
The invention relates in general to a package structure and a lead frame using the same, and more particularly to a package structure preventing the diffusion of adhesive via using the through holes and the grooves to form a rectangular shaped trace and a lead frame using the same.
2. Description of the Related Art
Semiconductor package technology covers a semiconductor chip by a molding compound to prevent the chip from getting moistured or collided. The microelectronic elements and circuits inside the chip are electrically connected to the external via a bump, a lead frame or a bonding wire. As various electronic products are provided and the demand for chips is increasing dramatically, the semiconductor package technology plays a crucial role in the development of today's industrial technology.
Referring to FIG. 1, a side view of a conventional package structure is shown. The conventional package structure 100 includes a lead frame 110, a chip 120, an epoxy 130 and a molding compound 140. The lead frame 110 has a first surface 110a and a second surface 110b opposite to the first surface 110a. The first surface 110a of the lead frame 110 has a chip adherent area 110c. The chip 120 is disposed on the chip adherent area 110c. The epoxy 130 is disposed between the chip 120 and the lead frame 110. The molding compound 140 covers the chip 120 to prevent the chip 120 from getting moistured or collided.
Referring to FIG. 2, a top view of a lead frame, a chip and an epoxy of FIG. 1 is shown. The lead frame 110 includes a plurality of through holes 111. The through holes 111 penetrate through the first surface 110a and the second surface 110b to be disposed around the chip adherent area 110c. The molding compound 140 of FIG. 1 flows from the first surface 110a to the through holes 111 and arrives at the second surface 110b of the lead frame 110, such that the structure of the lead frame 110 is strengthened.
The epoxy 130 is a sticky liquid. During the manufacturing process, the epoxy 130 is easy to be diffused but difficult to be maintained within the chip adherent area 110c. Especially when the chip 120 is disposed on the epoxy 130, the diffusing area of the epoxy 130 is even hard to control as shown in FIG. 1 and FIG. 2.
To enhance the structural strength of the package structure 100 has always been an aim to be achieved. The through holes 111 disclosed above are a design for enhancing the structure. However, the epoxy 130 is diffused on the lead frame 110 and severely affects the structural strength of the package structure 100. As shown in FIG. 1, in the diffusing area of the epoxy 130, the molding compound 140 fails to cover the lead frame 110 well. When the molding compound 140 is solidified, aperture and cleft are formed inside the package structure 100, severely deteriorating the structural strength of the package structure 100. Therefore, how to overcome the above problem has become an imminent issue to be resolved.